Field of the Invention
The invention relates in general to a layout method, an electronic device and a connector, and more particularly to a layout method, an electronic device and a connector with pairs of differential lines.
Description of the Related Art
Many portable devices provide display device to display video data. The Mobile Industry Processor Interface (hereinafter, MIPI) that transmits control signals by differential means is a transmission interface commonly applied to control a display panel.
FIG. 1A shows a schematic diagram of a display device based on MIPI. A display device 11 includes a display panel 11a and a display driver chip 11b. The display panel 11a is controlled by the display driver chip 11b. 
The display driver chip 11b receives signals via 19 conductive lines of a flexible printed circuit (hereinafter, FPC). These 19 conductive lines include ten differential lines, six ground shield lines (Gnd) and three control lines. It is assumed in FIG. 1A that, the ten differential lines are for transmitting four pairs of differential data signals (D0±, D1±, D2± and D3±), and one pair of differential clock signals (CLK±).
FIG. 1B shows a schematic diagram of an FPC. An FPC 13 has two connecting sides. The left connecting side is electrically connected to a display driver chip, and the right connecting side is electrically connector to a connector (not shown).
The connector is mounted on a printed circuit board (hereinafter, PCB) of a host end, and serves as a medium that transmits signals between the FPC 13 and the PCB. For example, the host end may be a main circuit of a cell phone or a portable DVD playback circuit.
The above combination of the FPC, the connector and the PCB is applied to various kinds of portable devices that support display functions. To allow the display device 11 to receive control signals from the host end, the same number of conducting wires are disposed at the FPC 13, the connector and the PCB.
The bandwidth required by MIPI gets larger as the resolution of a panel gets higher, and the number of differential line pairs required also increases. Further, the number of conductive lines (pins) involved in the connector utilized also increases as the number of differential line pairs increases, in a way that the occupied by the connector on the PCB expands as well. However, such occurrence of the increased pin count and the expanded hardware space is an issue that manufacturers of portable devices hope to avoid.